@haugstrup recently added a new feature for Max Match Play.
If a player leaves the tournament early you now have a choice between deleting all matches involving that player or leaving those matches intact. Choose the option that best fits your tournament.
I think it’s great to have this option, but using it does have the potential of causing some other trouble for the tournament. This problem comes up when you use the new option to not delete matches for someone leaves after playing an odd number of matches. I wrote up my thoughts on how the TD can adapt the tournament to handle this situation when it comes up. There’s no best answer here as they all have pros and cons. I suggest you pick a strategy (or a decision tree of strategies for different circumstances), write that plan into your IFPA calendar submission, and stick to it if the issue comes up.
Description of the problem
As the Deactivate player description says, “you can leave the games intact but risk having a player left over at the end without an opponent.” I think it’s easier to understand the scenario of “player left over without an opponent” if you think of it it as a “half-game problem”.
You have a tournament with Players A, B, and C.
Tournament duration is 2.
A plays B.
A plays C.
Player C leaves the tournament.
Now you’re stuck.
A has played 2 and can’t play any more, but B has only played 1 and needs to play 1 more.
To describe this problem more generally, you can think of each game as being two half-games. The total number of half-games that need to be played by people remaining in the tournament needs to be even for the pairings to work at the end. When player C leaves they take 1 half-game out of the pool of games to be played. There are a total of 0 half-games to be played from A and 1 half-game to be played from B. Every time you play another game you’re subtracting two half-games, so you’ll never get back to an even number of half-games even if you increase or decrease the duration.
Options for handling the problem
A. Deactivate the player who left then delete their most recent result. Their opponent from that game will have to play a game against someone else to replace their deleted game.
B. Include the player who left in pairings one more time. That opponent gets a free win. Then deactivate the player who left.
C. Do nothing when they leave and get lucky when a different player leaves later in the tournament also with an odd number of games played. (They balance each other out.)
D. At the end of the tournament, when the last pairing is created you’ll have 1 player waiting with 1 game to play and at least one active match with 2 players on their last game. Play that game as a 3-player game. Use adjust points to give the waiting player +1 point if they get 1st or 2nd.
E. At the end of the tournament, pair the player who needs a game with someone who already has the maximum number of games. This game is not recorded in match play. If the player who needs a game wins give them a +1 point adjustment. The points of the player who they’re paired against is not affected by the result of this game. (Recommendation to choose this player as someone who is one point ahead of the player who needs a game so they have some natural incentive to defend their spot in the standings rather than giving up a point and creating a tie.)
F. Increase the duration by 1. (Only works if you started with an even number of players.)
Combining options
You may want your tournament’s rules to lay out a plan for different solutions depending on the situation.
Here are some examples:
A + B: In the situation where a player leaves the tournament early we will evaluate whether that would result in a situation where the tournament ends with impossible pairings (e.g. the player had completed an odd number of matches). If it does and the departing player had won their previous match, that match result will be deleted and their previous opponent will get a chance at replaying that game with a different opponent. If the previous match was a loss for the departing player, then they will be included in pairing one more time and the player in the new pairing will get an automatic win (i.e. the player is not considered dropped until they do not show up for that newly paired match).
F + C + D: In the situation where a player leaves the tournament early we will evaluate whether that would result in a situation where the tournament ends with impossible pairings (e.g. the player had completed an odd number of matches). If the tournament had started with an even number of players we will increase the tournament duration by +1 match. Otherwise, we’ll wait until the end of the tournament before addressing the situation. If another player leaves later also with an odd number of games completed then no changes will be needed. If we get to the end of the tournament where creating matches results in one player left with a single game to play and all other players paired off for their final game, then we’ll randomly choose one of the games that was just created and will play that as a 3 player game. We’ll randomly determine player order for that game. Match result and Adjust Points will be used to record the result such that the 1st and 2nd place players both get a point and the 3rd place player does not get a point.
